Although many patents have been granted during the past 100 years for input keyboards, many problems remain unsolved. Numerous patents and other prior art documents have discussed the limitations and inadequacies of the universal or QWERTY keyboard for typists. An example of such a patent is U.S. Pat. No. 3,929,216 (Einbinder). Because of the limitations of the QWERTY keyboard, many previous patents for keyboards have focused on keyboard designs and key arrangements that are designed to increase input speeds, reduce fatigue, reduce errors, and the like. These designs and arrangements are generally targeted for use by people who are frequent and heavy users of keyboards and are of limited value for use as computer input devices by people who are casual, low frequency users without typing training, referred hereafter as non-typists.
Alphabetical keyboard arrangements, i.e., arrangements where the letter keys are simply arranged in alphabetical order, can potentially facilitate the use of keyboards by non-typists, but the obvious alphabetic arrangement of the letter keys in three horizontal rows, i.e., with the top row consisting of the letters a b c d e f g h i j, the second row of the letters k l m n n o p q r s and the third row of the letters t u v w x y z, has been found to be almost as difficult to use and learn as the QWERTY design. In this regard, it appears this obvious alphabetic design neglects important facts as to how humans process information and this apparently accounts for the learning difficulties generally encountered. A more complex alphabetical arrangement of keys, which is designed as part of a telegraphic key apparatus and is apparently not in use, is disclosed in U.S. Pat. No. 12,929 (White). The White patent discloses an arrangement where the keys are disposed in four horizontal rows with the four keys of each vertical column being arranged in alphabetical order. A recent patent which also provides for an alphabetical arrangement of keys is U.S. Pat. No. 4,180,337 (Otey et al). The Otey el al patent recognizes that non-typists need learning aids and that an intuitive ordering of keys in an alphabetic arrangement provides benefits of ease of use by infrequent users. The patent also discloses that in some circumstances one-handed use of a keyboard may have distinct advantages over two-handed use. However, the Otey et al patent focuses on the vowels in Western languages in an attempt to create a meaningful pattern for users. The keys of the keyboard disclosed therein are arranged in five primary rows with each primary row beginning with a vowel-representing key. Each vowel-representing key is followed by consonant representing keys and an alphabetical order is maintained. This keyboard arrangement suffers important disadvantages and most people will face two major difficulties with the keyboard design of the Otey et al patent. First, placing six keys in the third, fourth and fifth primary rows results in an arrangement wherein the short-term memory capacity of the user is exceeded, thus increasing the learning time of the arrangement. Second, placing six keys in a row requires awkward lateral hand-movements and encourages people to use four or five digits of the hand, resulting in weak and awkward thumb and fourth finger movements.
Other patents in this general field which are of possible interest include: U.S. Pat. Nos. 185,714 (Allen); 433,765 (Collins); 560,572 (Davis); 573,623 (Richards); 943,466 (Rowell); 1,292,319 (Hooper, Jr.); 1,336,122 (Banaji); 1,342,244 (Wolcott); 1,506,426 (Hoke); 2,040,248 (Dvorak et al); 2,080,457 (Bower); 2,167,150 (Haberfeld); 2,503,805 (Davidson et al); 2,827,145 (Anderson); 3,847,263 (X); 3,990,050 (Pitroda); 3,932,859 (Kyriakides et al); 3,925,779 (Gerstenhaber); 4,211,497 (Montgomery); 4,180,336 (Lonsdale); 4,244,659 (Malt); and 4,332,493 (Einbinder).